Method and apparatus to harden a software execution in random access memory
Example embodiments of the present invention relate to a system, apparatus and methods for preserving the integrity of a code to prevent it from being modified, maliciously or inadvertently, while it is in execution in the RAM of a computer platform. This method also may be referred to as code hardening. Code to be hardened in example embodiments of the present invention may be referred to as protected code. Example embodiments of the present invention are able to externally detect unauthorized stoppage of the hypervisor by employing ( 1 ) a launch-time metric of the protected code; ( 2 ) a run-time metric of the protected code; and ( 3 ) a liveliness indicator of the protected code.
1. A computer-implemented method comprising:
receiving, from a computer platform at an external verifier, a launch-time metric of stored protected code, wherein the launch-time metric comprises a first measurement of stored protected code in storage of the computer platform generated at a first launch time of the computer platform;
obtaining, from the computer platform at the external verifier, a run-time metric of the executed protected code, wherein the run-time metric comprises a second measurement of executed protected code in memory of the computer platform generated at a second run time after the first launch time but before a third validation time;
obtaining, from the computer platform at the external verifier, a liveliness indicator of the executed protected code, wherein the liveliness indicator is initialized according to a shared secret between the computer platform and the external verifier and is indicative of whether the executed protected code in memory of the computer platform has been stopped or altered between the second run time and the third validation time; and
validating, at the external verifier, the integrity of the executed protected code according to the launch-time metric, the run-time metric, and the liveliness indicator.
2. The method of claim 1 wherein validating, at the external verifier, the integrity of the executed protected code according to the launch-time metric, the run-time metric, and the liveliness indicator comprises:
determining whether the launch-time metric and the run-time metric are equivalent;
reporting an alert indicating compromise of the stored protected code if the launch-time metric and the run-time metric are not equivalent; and
determining whether the executed protected code is in a liveliness state if the launch-time metric and the run-time metric are equivalent.
3. The method of claim 2 wherein determining whether the executed protected code is in a liveliness state if the launch-time metric and the run-time metric are equivalent comprises:
determining if the liveliness indicator conforms to a liveliness protocol;
reporting an alert indicating compromise of the executed protected code if the liveliness indicator does not conform to the liveliness protocol; and
reporting validation of the executed protected code if the liveliness indicator does conform to the liveliness protocol.
4. The method of claim 3 wherein obtaining a liveliness indicator of the executed protected code from the computer platform comprises:
receiving an initialization seed from the computer platform;
initializing a one-way function of the liveliness protocol according to the initialization seed;
requesting the liveliness indicator from the computer platform if the launch-time metric and the run-time metric are equivalent; and
receiving the liveliness indicator.
5. The method of claim 4 wherein obtaining, from the computer platform at the external verifier, a run-time metric of the executed protected code comprises:
sending a request for the run-time metric from the external verifier to the computer platform; and
receiving the run-time metric from the computer platform at the external verifier, wherein the computer platform generates the run-time metric upon receipt of the request for the run-time metric by measuring the executed protected code at run time of the executed protected code.
6. A computer-implemented method comprising:
providing, from a computer platform to an external verifier, a launch-time metric of stored protected code, wherein the launch-time metric comprises a first measurement of stored protected code in storage of the computer platform generated at a first launch time of the computer platform;
providing, from a computer platform to an external verifier, a run-time metric of executed protected code, wherein the run-time metric comprises a second measurement of executed protected code in memory of the computer platform generated at a second run time after the first launch time but before a third validation time;
providing, from the computer platform to the external verifier, a liveliness indicator of the executed protected code, wherein the liveliness indicator is initialized according to a shared secret between the computer platform and the external verifier and is indicative of whether the executed protected code in memory of the computer platform has been stopped or altered between the second run time and the third validation time; and
receiving, from the external verifier at the computer platform, a notification regarding validity of the executed protected code determined according to the launch-time metric, the run-time metric, and the liveliness indicator.
7. The method of claim 6 wherein providing, from the computer platform to the external verifier, a liveliness indicator of the executed protected code comprises:
providing an initialization seed from the computer platform to the external verifier; and
initializing a one-way function of the liveliness protocol according to the initialization seed.
8. The method of claim 7
wherein providing, from a computer platform to an external verifier, a launch-time metric of stored protected code comprises:
measuring the stored protected code to generate the launch-time metric;
storing the launch-time metric in a physically protected environment; and
sending the launch-time metric from the computer platform to the external verifier;
wherein providing, from the computer platform to the external verifier, a run-time metric of executed protected code comprises:
receiving a request from the external verifier for the run-time metric;
measuring the executed protected code to generate the run-time metric; and
sending the run-time metric from the computer platform to the external verifier; and
wherein providing, from the computer platform to the external verifier, a liveliness indicator of the executed protected code further comprises:
receiving a request for the liveliness indicator from the external verifier if comparing the launch-time metric and the run-time metric at the external verifier succeeds;
calculating the liveliness indicator according to the liveliness protocol; and
sending the liveliness indicator from the computer platform to the external verifier.
9. An apparatus comprising:
a comparator unit configured to receive a launch-time metric of stored protected code from a computer platform and obtain a run-time metric of the executed protected code from the computer platform, wherein the launch-time metric comprises a first measurement of stored protected code in storage of the computer platform generated at a first launch time of the computer platform and wherein the run-time metric comprises a second measurement of executed protected code in memory of the computer platform generated at a second run time after the first launch time but before a third validation time; and
a verification unit configured to obtain a liveliness indicator of the executed protected code from the computer platform and validate the integrity of the executed protected code according to the launch-time metric, the run-time metric, and the liveliness indicator, wherein the liveliness indicator is initialized according to a shared secret between the computer platform and the external verifier and is indicative of whether the executed protected code in memory of the computer platform has been stopped or altered between the second run time and the third validation time.
10. The apparatus of claim 9
wherein the comparator unit is further configured to determine whether the launch-time metric and the run-time metric are equivalent and report an alert indicating compromise of the stored protected code if the launch-time metric and the run-time metric are not equivalent; and
wherein the verification unit is further configured to determine if the liveliness indicator conforms to a liveliness protocol, report an alert indicating compromise of the executed protected code if the liveliness indicator does not conform to the liveliness protocol, and report validation of the executed protected code if the liveliness indicator does conform to the liveliness protocol.
11. The apparatus of claim 10 wherein the verification unit is further configured to receive an initialization seed from the computer platform, initialize a one-way function of the liveliness protocol according to the initialization seed, request the liveliness indicator from the computer platform if the launch-time metric, and the run-time metric are equivalent, and receive the liveliness indicator.
12. An apparatus comprising:
a launch-time unit configured to provide a launch-time metric of stored protected code to an external verifier, wherein the launch-time metric comprises a first measurement of stored protected code in storage of the computer platform generated at a first launch time of the computer platform;
a run-time unit configured to provide a run-time metric of executed protected code to the external verifier, wherein the run-time metric comprises a second measurement of executed protected code in memory of the computer platform generated at a second run time after the first launch time but before a third validation time; and
a liveliness unit configured to provide a liveliness indicator of the executed protected code to the external verifier,
wherein the liveliness indicator is initialized according to a shared secret between the computer platform and the external verifier and is indicative of whether the executed protected code in memory of the computer platform has been stopped or altered between the second run time and the third validation time.
13. The apparatus of claim 12
wherein the launch-time unit is further configured to measure the stored protected code to generate the launch-time metric, store the launch-time metric in a physically protected environment, and send the launch-time metric to the external verifier;
wherein the run-time unit is further configured to receive a request from the external verifier for the run-time metric, measure the executed protected code to generate the run-time metric, and send the run-time metric to the external verifier; and
wherein the liveliness unit is further configured to provide an initialization seed to the external verifier, initialize a one-way function of a liveliness protocol according to the initialization seed, receive a request for the liveliness indicator from the external verifier if comparing the launch-time metric and the run-time metric at the external verifier succeeds, calculate the liveliness indicator according to the one-way function of the liveliness protocol initialized by the initialization seed, and provide the liveliness indicator to the external verifier.
14. A system comprising
a computer platform comprising:
a launch-time unit configured to provide a launch-time metric of stored protected code to an external verifier;
a run-time unit configured to provide a run-time metric of executed protected code to an external verifier; and
a liveliness unit configured to provide a liveliness indicator of the executed protected code to the external verifier; and an external verifier comprising:
a comparator unit configured to receive a launch-time metric of stored protected code from the computer platform and obtain a run-time metric of the executed protected code from the computer platform; and
a verification unit configured to obtain a liveliness indicator of the executed protected code from the computer platform and a validate the integrity of the executed protected code according to the launch-time metric, the run-time metric, and the liveliness;
wherein the launch-time metric comprises a first measurement of stored protected code in storage of the computer platform generated at a first launch time of the computer platform;
wherein the run-time metric comprises a second measurement of executed protected code in memory of the computer platform generated at a second time after the first launch time but before a third validation time; and
wherein the liveliness indicator is initialized according to a shared secret between the computer platform and the external verifier and is indicative of whether the executed protected code in memory of the computer platform has been stopped or altered between the second run time and the third validation time.
15. The system of claim 14
wherein the launch-time unit is further configured to measure the stored protected code to generate the launch-time metric, store the launch-time metric in a physically protected environment, and send the launch-time metric to the external verifier;
wherein the run-time unit is further configured to receive a request from the external verifier for the run-time metric, measure the executed protected code to generate the run-time metric, and send the run-time metric to the external verifier; and
wherein the liveliness unit is further configured to provide an initialization seed to the external verifier, initialize a one-way function of a liveliness protocol according to the initialization seed, receive a request for the liveliness indicator from the external verifier if comparing the launch-time metric and the run-time metric at the external verifier succeeds, calculate the liveliness indicator according to the one-way function of the liveliness protocol initialized by the initialization seed, and provide the liveliness indicator to the external verifier.
16. The system of claim 15
wherein the comparator unit is further configured to determine whether the launch-time metric and the run-time metric are equivalent, report an alert indicating compromise of the stored protected code if the launch-time metric and the run-time metric are not equivalent, and request the liveliness indicator if the launch-time metric and the run-time metric are equivalent; and
wherein the verification unit is further configured to receive an initialization seed from the computer platform, initialize the one-way function of a liveliness protocol according to the initialization seed, receive the liveliness indicator of the executed protected code from the computer platform according to the liveliness protocol, determine if the liveliness indicator conforms to the one-way function of the liveliness protocol initialized according to the initialization seed, report an alert indicating the compromise of the executed protected code if the liveliness indicator does not conform to the liveliness protocol, and report validation of the executed protected code if the liveliness indicator does conform to the liveliness protocol.
17. A computer program product having a non-transitory computer readable storage medium operable to store computer program logic embodied in computer program code encoded thereon for validating integrity of executed protected code in memory of a computer platform at an external verifier comprising:
computer program code for receiving, from the computer platform at the external verifier, a launch-time metric of stored protected code, wherein the launch-time metric comprises a first measurement of stored protected code in storage of the computer platform generated at a first launch time of the computer platform;
computer program code for obtaining, from the computer platform at the external verifier, a run-time metric of the executed protected code, wherein the run-time metric comprises a second measurement of executed protected code in memory of the computer platform generated at a second run time after the first launch time but before a third validation time;
computer program code for obtaining, from the computer platform at the external verifier, a liveliness indicator of the executed protected code, wherein the liveliness indicator is initialized according to a shared secret between the computer platform and the external verifier and is indicative of whether the executed protected code in memory of the computer platform has been stopped or altered between the second run time and the third validation time; and
computer program code for validating, at the external verifier, the integrity of the executed protected code at according to the launch-time metric, the run-time metric, and the liveliness indicator.
18. The computer program product of claim 17 wherein computer program code for validating, at the external verifier, the integrity of the executed protected code according to the launch-time metric, the run-time metric, and the liveliness indicator comprises:
computer program code for determining whether the launch-time metric and the run-time metric are equivalent;
computer program code for reporting an alert indicating compromise of the stored protected code if the launch-time metric and the run-time metric are not equivalent; and
computer program code for determining whether the executed protected code is in a liveliness state if the launch-time metric and the run-time metric are equivalent.
19. The computer program product of claim 18 wherein computer program code for determining whether the executed protected code is in a liveliness state if the launch-time metric and the run-time metric are equivalent comprises:
computer program code for determining if the liveliness indicator conforms to a liveliness protocol;
computer program code for reporting an alert indicating compromise of the executed protected code if the liveliness indicator does not conform to the liveliness protocol; and
computer program code for reporting validation of the executed protected code if the liveliness indicator does conform to the liveliness protocol.
20. The computer program product of claim 19 wherein computer program code for obtaining a liveliness indicator of the executed protected code from the computer platform comprises:
computer program code for receiving an initialization seed from the computer platform;
computer program code for initializing a one-way function of the liveliness protocol according to the initialization seed;
computer program code for requesting the liveliness indicator from the computer platform if the launch-time metric and the run-time metric are equivalent; and
computer program code for receiving the liveliness indicator.
21. The computer program product of claim 20 wherein computer program code for obtaining, from the computer platform at the external verifier, a run-time metric of the executed protected code comprises:
computer program code for sending a request for the run-time metric from the external verifier to the computer platform; and
computer program code for receiving the run-time metric from the computer platform at the external verifier, wherein the computer platform generates the run-time metric upon receipt of the request for the run-time metric by measuring the executed protected code at run time of the executed protected code.
22. A computer program product having a non-transitory computer readable storage medium operable to store computer program logic embodied in computer program code encoded thereon for validating integrity of executed protected code in memory of a computer platform with an external verifier comprising:
computer program code for providing, from the computer platform to the external verifier, a launch-time metric of stored protected code, wherein the launch-time metric comprises a first measurement of stored protected code in storage of the computer platform generated a first launch time of the computer platform;
computer program code for providing, from the computer platform to the external verifier, a run-time metric of executed protected code, wherein the run-time metric comprises a second measurement of executed protected code in memory of the computer platform generated at a second run time after the first launch time but before a third validation time; and
computer program code for providing, from the computer platform to the external verifier, a liveliness indicator of the executed protected code, wherein the liveliness indicator is initialized according to a shared secret between the computer platform and the external verifier and is indicative of whether the executed protected code in memory of the computer platform has been stopped or altered between the second run time and the third validation time.
23. The computer program product of claim 22 wherein computer program code providing, from the computer platform to the external verifier, a liveliness indicator of the executed protected code comprises:
computer program code for providing an initialization seed from the computer platform to the external verifier; and
computer program code for initializing a one-way function of the liveliness protocol according to the initialization seed.
24. The computer program product of claim 23
wherein computer program code for providing, from a computer platform to an external verifier, a launch-time metric of the stored protected code comprises:
computer program code for measuring the stored protected code to generate the launch-time metric;
computer program code for storing the launch-time metric in a physically protected environment; and
computer program code for sending the launch-time metric from the computer platform to the external verifier;
wherein computer program code for providing, from the computer platform to the external verifier, a run-time metric of the executed protected code comprises:
computer program code for receiving a request from the external verifier for the run-time metric;
computer program code for measuring the executed protected code to generate the run-time metric; and
computer program code for sending the run-time metric from the computer platform to the external verifier; and
wherein computer program code for providing, from the computer platform to the external verifier, a liveliness indicator of the executed protected code further comprises:
computer program code for receiving a request for the liveliness indicator from the external verifier if comparing the launch-time metric and the run-time metric at the external verifier succeeds;
computer program code for calculating the liveliness indicator according to the liveliness protocol; and
computer program code for sending the liveliness indicator from the computer platform to the external verifier.